This application claims benefit of Japanese Patent Application No. 2002-246893 filed on Aug. 27, 2002, the contents of which are incorporated by the reference.
The present invention relates to techniques of notification in (public) wireless LAN service area and, more particularly, to a device or system for and a method of providing, when providing a display as to whether the user is in the service area of a hot spot service, a clear display as to whether the pertinent service area belongs to a hot spot dealer, which the user has subscribed to, or to a dealer in roaming contract relation to the hot spot dealer.
At present, hot spot services using wireless LAN of IEEE 802.11b system is attracting pronounced attentions.
As the hot spot service, communication dealers, managers of a shop or a restaurant, etc. install wireless LAN access points in airport lobbies, shops, restaurants and also many places where many people come to, provide high speed wireless data communication services. The users can make use of the service for WWW (world wide web) browser or transmission and reception of electronic mails by using personal computers with wireless LAN (local area network) cards mounted thereon or PDA (personal digital assistants).
The user can receive the service by making a contract with the pertinent hot spot service dealer. While the hot spot service is raised in various places by various dealers, the area which is covered by a wireless LAN access point is as large as a hundred and several ten meters outdoors and several ten meters indoors. 2.4 GHz having a strong directivity is used. In IEEE 802.11b, a new modification system is added to a conventional transmission system using a 2.4 GHz band to permit communication utmost at 11 Mbps. An enormous property burden on a dealer to cover main regions over the country of Japan. It is thus thought that a hot spot dealer intends to expand its covered area by concluding a roaming contract with a different dealer. In this case, it is thought that the user intending to obtain service in the area of a dealer in roaming contrast relation to the hot spot dealer subscribed by the user, has to pay an extra communication fee.
In the mean time, the user can have a rough intelligence about whether the user is now in the service area, with a map of the service area notified by the hot spot dealer and software in a wireless LAN product to show electric field intensity relevant thereto. The software provides the electric field intensity of a wireless LAN channel, via which ESS (Extended Service Set) ID designated by the user is transmitted. As a measure concerning the security between access point (AP) and station (STA), an authentication procedure is executed between AP and STA through open system authentication in which ID is exchanged in two steps between AP and STA, and/or a common key authentication is executed in which ID is ciphered and exchanged in four steps. As for the actual product, group setting is made in the name of “ESS ID” or the like.
When the ESS ID is designated by the hot spot dealer, rough intelligence about whether the user is in the service area of the dealer can be obtained by setting the software providing the electric field intensity.
In the above background, the following problem is raised in connection with hot spot service reception by the user.
Where ESS ID is given for identifying the hot spot dealer, using the above indicator the user can not check whether the user is in the service area of a hot spot dealer in roaming contract relation to the own subscribed hot spot dealer, but can check only whether the user is in the service area of the own hot spot dealer.
Also, where the hot spot dealer in the roaming contract relation uses the same ESS ID, the user cannot distinguish whether the user is in the area of the own subscribed dealer or in the area of the roaming contract relation dealer.
In the viewpoint of the user side, it is more convenient that display is made not only as to whether the user is in the service area of the own subscribed hot spot dealer but also as to whether the user is in the service area of the roaming contract relation dealer in roaming contract relation is made.
Also, from the consideration that receiving service in the area of the dealer in roaming contract relation requires payment of an extra fee, it is more convenient to provide a display, which permits clear distinguish as to whether the user is in the area of the own subscribed dealer or in the area of the roaming contract relation dealer instead of providing display of the two cases in the same fashion.
As further prior art examples, Japanese Patent Laid-Open No. 10-145833 discloses a system, which provides for a mobile terminal a step of detecting a roaming call at the time of call transmission and reception, a step of checking, with reference to a roaming control table, as to whether a wireless base station of the dealer, which is subscribed to by the mobile terminal, is in the overlap area, and a step of making a hand-over request when the pertinent wireless base station is found, thus permitting communication via the dealer's wireless base station as much as possible even in the case that roaming call is allowed. Japanese Patent Laid-Open No. 11-004482 discloses a mobile telephone set, which provides for a call transmission process comprising a step of retrieving for a base station, which permits call transmission in the status of the base station of each service company, a step of measuring the electric intensity of the base station permitting the call transmission and a step of selecting the best base station, and has a function of transmitting a call with ID of a good wave status service company without any designation by the user but automatically. A further hot spot identification teaching, Japanese Patent Laid-Open No. 2001-508245 is referred to.